165   var observer = nullProtoObject();
166   observer.callback = callback;
167   observer.accept = acceptList;
168   return observer;
172 function ObserverGetCallback(observer) {  argument
173   return IS_CALLABLE(observer) ? observer : observer.callback;
177 function ObserverGetAcceptTypes(observer) {  argument
178   return IS_CALLABLE(observer) ? defaultAcceptTypes : observer.accept;
182 function ObserverIsActive(observer, objectInfo) {  argument
184                                ObserverGetAcceptTypes(observer));
244     var observer = objectInfo.changeObservers;
245     var callback = ObserverGetCallback(observer);
249     objectInfo.changeObservers[priority] = observer;
256   var observer = ObserverCreate(callback, acceptList);
259     objectInfo.changeObservers = observer;
265   objectInfo.changeObservers[priority] = observer;
291     var observer = objectInfo.changeObservers[priority];
292     if (!IS_NULL(observer) && ObserverIsActive(observer, objectInfo))
433 function ObserverEnqueueIfActive(observer, objectInfo, changeRecord) {  argument
434   if (!ObserverIsActive(observer, objectInfo) ||
435       !TypeMapHasType(ObserverGetAcceptTypes(observer), changeRecord.type)) {
439   var callback = ObserverGetCallback(observer);
491     var observer = objectInfo.changeObservers;
492     ObserverEnqueueIfActive(observer, objectInfo, changeRecord);
497     var observer = objectInfo.changeObservers[priority];
498     if (IS_NULL(observer))
500     ObserverEnqueueIfActive(observer, objectInfo, changeRecord);